Top down 2d shooter enemy control

Questions & Answers
1

In my top down 2d game I created an int variable called dir
I assigned him a random number between 0 and 3
I made a switch case where if it is 0 the enemy goes straight if 1 the enemy goes diagonally left if it is 2 the enemy goes right diagonal

this is the part of the code
but it does not work

// move the enemy

    Vector2 pos = transform.position;
    Vector2 velocity;

    int dir = (int)Random.Range(0, 3);
    Debug.Log(dir);

    switch (dir)
    {
        case 0:
            velocity = new Vector2(0, -speedEnemy * Time.deltaTime);
            this.transform.Translate(velocity, Space.World);
            Debug.Log("DRITTO");
            break;

        case 1:
            velocity = new Vector2(-speedEnemy * Time.deltaTime, -speedEnemy * Time.deltaTime);
            this.transform.Translate(velocity, Space.World);
            Debug.Log("SINISTRA");
            break;

        case 2:
            velocity = new Vector2(speedEnemy * Time.deltaTime, -speedEnemy * Time.deltaTime);
            this.transform.Translate(velocity, Space.World);
            Debug.Log("DESTRA");
            break;
    }

though the switch case works regularly the enemy always goes left diagonally and not with a smooth movement

my goal is to create random the direction of the enemies

because? what am I doing wrong?

Many thanks for your help

2

You have to Update the position based upon current position of Object. So your code will become.

     Vector2 pos = transform.position;
     Vector2 velocity;
     int dir = (int)Random.Range(0, 3);
     Debug.Log(dir);
     switch (dir)
     {
         case 0:
             // Use current value as starting 
             velocity = new Vector2( this.transform.position.x + 0, this.transform.position.y -speedEnemy * Time.deltaTime);
             this.transform.Translate(velocity, Space.World);
             Debug.Log("DRITTO");
             break;
         case 1:
             velocity = new Vector2(this.transform.position.x-speedEnemy * Time.deltaTime, this.transform.position.y -speedEnemy * Time.deltaTime);
             this.transform.Translate(velocity, Space.World);
             Debug.Log("SINISTRA");
             break;
         case 2:
             velocity = new Vector2( this.transform.position.x+speedEnemy * Time.deltaTime, this.transform.position.y -speedEnemy * Time.deltaTime);
             this.transform.Translate(velocity, Space.World);
             Debug.Log("DESTRA");
             break;
     }
3

hi @dev-waqas,

many tanks i try but now thr code give the follow error

transform.position assign attempt for ‘cell_white(Clone)’ is not valid. Input position is { 153413570376001570000000000000000000000.000000, Infinity, 0.000000 }.
UnityEngine.Transform:Translate(Vector3, Space)
EnemyControl:Update() (at Assets/Scripts/EnemyControl.cs:40)

I have 4 enemy cell_white, cell_red,cell_black,cell_yellow

this is the code that i use for eneny spawn random

public GameObject[] EnemiesPrefab;


float maxSpawnRateInSecond = 5f;

// Use this for initialization
void Start () {

   
}

// Update is called once per frame
void Update () {
	
}

void SpawnEnemy()
{
    // Botton left point of the screen
    Vector2 min = Camera.main.ViewportToWorldPoint(new Vector2(0, 0));

    // Top right point of the screen
    Vector2 max = Camera.main.ViewportToWorldPoint(new Vector2(1, 1));

    int randEnemy;
    randEnemy = Random.Range(0, EnemiesPrefab.Length);

    // Instantiate an enemy
    GameObject anEnemy = (GameObject)Instantiate(EnemiesPrefab[randEnemy]);
    anEnemy.transform.position = new Vector2(Random.Range(min.x, max.x), max.y);

    // Schedule when spawn next enemy
    ScheduleNextEnemySpawn();
}

// Schedule when spawn next enemy
void ScheduleNextEnemySpawn()
{
    float spawnInSeconds;

    if (maxSpawnRateInSecond > 1f)
    {
        // Pixk a number between 1 and maxSpawnRateInSecond
        spawnInSeconds = Random.Range(1f, maxSpawnRateInSecond);
    }
    else
        spawnInSeconds = 1f;
    Invoke("SpawnEnemy", spawnInSeconds);
}

// Method to increase the difficult of the game
void IncreaseSpawnRate()
{
    if (maxSpawnRateInSecond > 1f)
        maxSpawnRateInSecond--;
    if (maxSpawnRateInSecond == 1f)
        CancelInvoke("IncreaseSpawnRate");
}

// Method to start enemy spawner
public void ScheduleEnemySpawner()
{
    Invoke("SpawnEnemy", maxSpawnRateInSecond);

    // Increase spawn rate every 30 seconds
    InvokeRepeating("IncreaseSpawnRate", 0f, 30f);
}

// Method to stop enemy spawner
public void UnscheduleEnemySpawner()
{
    CancelInvoke("SpawnEnemy");
    CancelInvoke("IncreaseSpawnRate");
}

many thanks